Understanding what is relevant on a food label for your own unique nutrition needs is a key step in managing your health.

If you have high blood pressure, what are your options? From a dietary perspective, the headlines would tell you to reduce your sodium intake, but which nutrients, if any, should you try to include more of? According to a new compilation of data from 22 previous studies, taking a magnesium supplement might do you some good. While this is good news for those battling their blood pressure, it is simply the latest finding that suggests bumping up your magnesium intake may do your body an awful lot of good.

Magnesium and blood pressure

According to the meta-analysis, published in the European Journal of Clinical Nutrition, taking a magnesium supplement can reduce systolic (that’s the top number) blood pressure by three to four points, and diastolic (the bottom number) blood pressure by two to three points. While this change is not large enough to bring a hypertensive patient’s blood pressure back to normal (normal blood pressure is under 120/80, while hypertension is 140/90 or higher), the result is still considered clinically significant. Notably, however, the best results were observed in those taking an average dose of 370 mg of magnesium citrate per day, which is actually above Health Canada’s tolerable upper intake level of 350 mg per day via supplements. Having said that, the 350 mg ceiling was established because of the potential for diarrhea, a side effect that can be minimized by gradually increasing supplementation.

These results reinforce previous findings from the DASH (Dietary Approaches to Stop Hypertension) study, which found that a diet that includes plenty of foods rich in magnesium, potassium, calcium and fibre can help to control blood pressure, even without reducing sodium intake (cutting sodium helped make the drop even more pronounced). Notably, the DASH study examined the effect of food on blood pressure; the new meta-analysis suggests that taking magnesium in supplemental form could also be of some benefit.

Magnesium and... everything else

Aside from its role in blood pressure management, magnesium also influences our health in a variety of ways, including the health of our hearts and our bones. High doses (up to 600 mg per day, which is usually taken in divided doses, morning and night) may also be helpful in managing constipation, easing muscle pain, and reducing the severity of migraine headaches. Magnesium may also help to support insulin sensitivity, the hormone that helps to control blood sugar, and a recent meta-analysis published in the American Journal of Clinical Nutrition found that, for every 100 mg increase in magnesium intake, the risk of stroke dropped by 9 per cent.

Now, here's the bad news: While the data tell us of magnesium's importance to our health, the reality is most Canadians do not meet their needs. While adult women need 320 mg per day, and men 420 mg per day, magnesium-rich foods simply aren’t all that popular in the North American diet. For example, several varieties of nuts and seeds, including pumpkin seeds, Brazil nuts, almonds, and cashews are excellent sources of magnesium, but many people still avoid these foods out of fear of the fat content (if you are reading this, hear me now: Stop hating on nuts! They are fantastically nutritious! I’m not kidding! Try to aim for a handful per day, but don’t overdo it, as they are high in calories). Other magnesium-rich foods include beans and legumes, whole grains, leafy greens, and fish: again, not exactly the stuff you see in the food court or the drive-through.

Supplemental notes

While increasing magnesium through your diet is your best bet, if you do decide to take a supplement, start with 50 to 100 mg per day, and increase the dose slowly, usually in 50-100 mg increments every few days to avoid diarrhea. Those who have achy, restless muscles often find that taking magnesium at night helps improve sleep, and the same muscle-relaxing effect also makes magnesium helpful for those struggling with constipation.

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